From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Waychison Subject: Re: [NFS] RE: multiple servers per automount Date: Tue, 14 Oct 2003 11:52:22 -0400 Sender: autofs-bounces@linux.kernel.org Message-ID: <3F8C1BB6.9010202@sun.com> References: Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-reply-to: List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: autofs-bounces@linux.kernel.org Content-Type: text/plain; format="flowed"; charset="us-ascii" To: Ian Kent Cc: "Ogden, Aaron A." , autofs mailing list , nfs@lists.sourceforge.net, Kernel Mailing List , Joseph V Moss Ian Kent wrote: >On Tue, 14 Oct 2003, Joseph V Moss wrote: > > > >>The limit is 800 as others have stated. Although, it can be less than that >>if something else is already using up some of the reserved UDP ports. >> >>I wrote a patch long ago against a 2.2.x kernel to enable it to use >>multiple majors for NFS mounts (like the patches now common in several >>distros). I then ran into the 800 limit in the RPC layer. After changing >>the RPC layer to count up from 0, instead of down from 800, with no real >>upper limit, I was able to mount more than 2000 NFS filesystems simultaneously. >>I'm sure I could have done many thousand if I had had that many filesystems >>around to mount. Obviously, after 1024, it wasn't using reserved ports >>anymore, but it didn't seem to matter. >> >>Unfortunately, while the changes to NFS were easy to port to the 2.4 kernel, >>the RPC layer is different enough between 2.2 and 2.4 that it didn't work >>right off. Bumping it up to somewhere around 1024 should work, but using >>non-reserved ports didn't seem to work when I made a simple attempt. >> >>Of course, the real fix for the NFS layer is the expansion of the minor >>numbers that's already occurred in 2.6 and the RPC layer problems should >>be fixed by multiplexing multiple mounts on the same port. >> >> >> >> > >I don't see that expansion in 2.6 (test6). It looks to me like the >allocation is done in set_anon_super (in fs/super.c) and that looks like >it is restricted to 256. Please correct this for me. I can't see how there >is any change to the number of unnmaed devices. > > > Here is the quick fix for this in RH 2.1AS kernels: http://www.kernelnewbies.org/kernels/rh21as/SOURCES/linux-2.4.9-moreunnamed.patch It makes unnamed block devices use majors 12, 14, 38, 39, as well as 0. I don't know if anyone is working out a better scheme for get_unnamed_dev in 2.6 yet. It does need to be done though. A simple patch for 2.6 would maybe see the unnamed_dev_in_use bitmap grow to PAGE_SIZE, automatically allowing for 32768 unnamed devices. Mike Waychison From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262601AbTJNPxO (ORCPT ); Tue, 14 Oct 2003 11:53:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262596AbTJNPxO (ORCPT ); Tue, 14 Oct 2003 11:53:14 -0400 Received: from nwkea-mail-1.sun.com ([192.18.42.13]:21176 "EHLO nwkea-mail-1.sun.com") by vger.kernel.org with ESMTP id S262601AbTJNPxM (ORCPT ); Tue, 14 Oct 2003 11:53:12 -0400 Date: Tue, 14 Oct 2003 11:52:22 -0400 From: Mike Waychison Subject: Re: [NFS] RE: [autofs] multiple servers per automount In-reply-to: To: Ian Kent Cc: Joseph V Moss , "Ogden, Aaron A." , autofs mailing list , nfs@lists.sourceforge.net, Kernel Mailing List Message-id: <3F8C1BB6.9010202@sun.com> MIME-version: 1.0 Content-type: text/plain; format=flowed; charset=ISO-8859-1 Content-transfer-encoding: 7bit X-Accept-Language: en User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.3.1) Gecko/20030618 Debian/1.3.1-3 References: Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Ian Kent wrote: >On Tue, 14 Oct 2003, Joseph V Moss wrote: > > > >>The limit is 800 as others have stated. Although, it can be less than that >>if something else is already using up some of the reserved UDP ports. >> >>I wrote a patch long ago against a 2.2.x kernel to enable it to use >>multiple majors for NFS mounts (like the patches now common in several >>distros). I then ran into the 800 limit in the RPC layer. After changing >>the RPC layer to count up from 0, instead of down from 800, with no real >>upper limit, I was able to mount more than 2000 NFS filesystems simultaneously. >>I'm sure I could have done many thousand if I had had that many filesystems >>around to mount. Obviously, after 1024, it wasn't using reserved ports >>anymore, but it didn't seem to matter. >> >>Unfortunately, while the changes to NFS were easy to port to the 2.4 kernel, >>the RPC layer is different enough between 2.2 and 2.4 that it didn't work >>right off. Bumping it up to somewhere around 1024 should work, but using >>non-reserved ports didn't seem to work when I made a simple attempt. >> >>Of course, the real fix for the NFS layer is the expansion of the minor >>numbers that's already occurred in 2.6 and the RPC layer problems should >>be fixed by multiplexing multiple mounts on the same port. >> >> >> >> > >I don't see that expansion in 2.6 (test6). It looks to me like the >allocation is done in set_anon_super (in fs/super.c) and that looks like >it is restricted to 256. Please correct this for me. I can't see how there >is any change to the number of unnmaed devices. > > > Here is the quick fix for this in RH 2.1AS kernels: http://www.kernelnewbies.org/kernels/rh21as/SOURCES/linux-2.4.9-moreunnamed.patch It makes unnamed block devices use majors 12, 14, 38, 39, as well as 0. I don't know if anyone is working out a better scheme for get_unnamed_dev in 2.6 yet. It does need to be done though. A simple patch for 2.6 would maybe see the unnamed_dev_in_use bitmap grow to PAGE_SIZE, automatically allowing for 32768 unnamed devices. Mike Waychison